Performance testing system and method for air conditioner

ABSTRACT

A system for conducting performance tests of an air conditioner by operation modes, the system includes a test loader for loading an air conditioner to be tested; and a control unit for switching an operation mode of the air conditioner loaded on the test loader in order of cooling and heating operation modes at a preset lowest operating frequency and cooling and heating operation modes at a preset rated operating frequency, and executing the switched operation mode. Further, the system for conducting performance tests of an air conditioner by operation modes includes a checking unit for checking the existence of a malfunction in preset performances whenever each of the operation modes is executed; and a warning unit for visually and acoustically warning the check result on the existence of a malfunction in each of the operation modes.

FIELD OF THE INVENTION

The present invention relates to a performance testing technique for an air conditioner, and more specifically, to a performance testing system and method for an air conditioner, which are suitable for executing performance tests of the air conditioner during both cooling and heating operations at high speed.

BACKGROUND OF THE INVENTION

As well-known in the art, a typical air conditioner has a structure as shown in FIG. 1 as one example.

Referring to FIG. 1, the typical air conditioner is largely divided into an outdoor unit 110 and an indoor unit 120. The outdoor unit 110 is constituted by a compressor 111, a four-way valve 112, an outdoor heat exchanger 113, an electronic expansion valve (EEV) 114, an accumulator 115, an outdoor fan 116, and so forth. The indoor unit 120 is constituted by an indoor heat exchanger 121, an indoor fan 123, and so forth.

During a cooling operation of the typical air conditioner with the structure mentioned above, a high temperature, high pressure gaseous refrigerant compressed in the compressor 111 is introduced, via the four-way valve 112, into the outdoor heat exchanger 113 that functions as a condenser. This high-pressure gaseous refrigerant undergoes heat exchange, through the outdoor heat exchanger 113, with outdoor air of outdoor temperature which is lower than the refrigerant temperature, to be condensed to a high pressure state. Here, the outdoor fan 116 is driven by an outdoor fan motor (not shown), and serves to forcibly ventilate the outdoor air.

As the high-pressure condensed gaseous refrigerant passes through the EEV 114, it turns to low temperature, low pressure liquid refrigerant by throttling, and is conveyed to the indoor heat exchanger 121 of the indoor unit 120. Here, the indoor fan 123 is driven by an indoor fan motor (not shown), and serves to forcibly ventilate the indoor air.

Next, the refrigerant in a liquid state is evaporated through heat exchange with indoor air at the indoor heat exchanger 121 functioning as an evaporator. After evaporation, the low temperature, low pressure gaseous refrigerant flows back to the outdoor unit 110 along a circulation line, in which it passes through the four-way valve 112 and is introduced again into the compressor 111 via the accumulator 115. Here, the accumulator 115 serves to completely change the refrigerant being introduced into the compressor 111 into gas.

Moreover, during a heating operation of the typical air conditioner with the structure stated above, the refrigerant flow direction at the four-way valve 112 is reversed, so the refrigerant flows in opposite direction from the refrigerant flow during the cooling operation set forth above. At this time, since the indoor heat exchanger 121 functions as a condenser differently from the cooling operation, warm air is circulated again into the indoor environment by the indoor fan 123. That is, the refrigerant flow during the heating operation of the air conditioner follows the circulation line, such as, the compressor 111->the four-way valve 112->the indoor heat exchanger 121->the EEV 114->the outdoor heat exchanger 113->the four-way valve 112->the accumulator 115->the compressor 111.

Meanwhile, in terms of the reliability of a finished product, it is necessary for an air conditioner operating by the refrigerant circulation line described above to undergo various types of performance test (inspection) in the cooling and heating operations.

Here, examples of air conditioner performance test include vibration level and noise level during the cooling and heating operations, existence of compression defects, switching state of the four-way valve during switching between the cooling and heating operations, normal operational states of various sensors therein, normal operational state of a pressure switch, and so on.

For the above-stated performance tests, in the conventional test method, an engineer (or worker) manually operated an air conditioner to be tested by operation modes (that is, cooling and heating operations at the lowest operating frequency, and cooling and heating operations at rated operating frequency), and then tested the performance of the air conditioner by using various equipments (vibration sensor, noise sensor, oscilloscope, and the like).

In other words, in accordance with the conventional method, the engineer conducts performance testing on an air conditioner through a series of processes as follows. First of all, the engineer sets the operation mode of the air conditioner to a cooling operation mode to test a variety of performances at the lowest operating frequency. And then, the engineer manually switches the operation mode to a heating operation mode, and repeats the performance testing at the lowest operating frequency. Next, the engineer sets the air conditioner to a cooling operation mode to test a variety of performances at the rated operating frequency. Lastly, the engineer manually switches the operation mode to a heating operation mode, and repeats the performance testing at the rated operating frequency.

In the conventional performance test method, however, since the engineer has to manually operate the operation modes of the air conditioner in sequence to conduct a variety of performance tests, such a performance testing was a tedious and time consuming task. These problems eventually led to a reduction in productivity of air conditioners.

Moreover, because various kinds of performance tests were done manually by the engineer, the degree of accuracy of the performance test results is questionable. Such a problem acts as another factor that decreases the reliability of a finished product.

SUMMARY OF THE INVENTION

It is, therefore, a primary object of the present invention to provide a performance testing system and method for an air conditioner, which are capable of automatically executing performance tests of the air conditioner in each operation mode.

It is another object of the present invention to provide a performance testing system and method for an air conditioner, which are capable of automatically conducting performance tests of the air conditioner in each operation mode and automatically offering performance test results by operation modes in visible and acoustic alarms.

In accordance with one aspect of the present invention, there is provided a system for conducting performance tests of an air conditioner by operation modes, the system including: a test loader for loading an air conditioner to be tested; a control unit for switching an operation mode of the air conditioner loaded on the test loader in order of cooling and heating operation modes at a preset lowest operating frequency and cooling and heating operation modes at a preset rated operating frequency, and executing the switched operation mode; a checking unit for checking the existence of a malfunction in preset performances whenever each of the operation modes is executed; and a warning unit for visually and acoustically warning the check result on the existence of a malfunction in each of the operation modes.

It is preferable that the system further include a display unit for accumulating check results on the existence of a malfunction in each of the operation modes, and displaying, on a monitor, the accumulated check results as final performance test results.

Further, it is preferable that the warning unit includes: an LED for visually displaying the check result on the existence of a malfunction in each of the operation modes; and a speaker for acoustically warning the check result on the existence of a malfunction in each of the operation modes.

Further, it is also preferable that the various kinds of preset performances include at least one of vibration level, noise level, existence of compression defects, switching state of the four-way valve, and normal operational states of sensors.

In accordance with another aspect of the present invention, there is provided a method for conducting performance tests of an air conditioner by operation modes, the method including the steps of: loading an air conditioner to be tested on a test loader; operating the air conditioner in a cooling operation mode at a preset lowest operating frequency in response to a test mode start operation; performing a first check on the existence of a malfunction in preset performances during the cooling operation at the preset lowest operating frequency; automatically switching the air conditioner to a heating operation mode after the first check is executed for a specified amount of time, and operating the air conditioner at the preset lowest operating frequency; conducting a second check on the existence of a malfunction in preset performances during the heating operation at the preset lowest operating frequency; automatically switching the air conditioner to a cooling operation mode after the second check is executed for a specified amount of time, and operating the air conditioner at a preset rated operating frequency; carrying out a third check on the existence of a malfunction in preset performances during the cooling operation at the preset rated operating frequency; automatically switching the air conditioner to a heating operation mode after the third check is executed for a specified amount of time, and operating the air conditioner at the preset rated operating frequency; performing a fourth check on the existence of a malfunction in preset performances during the heating operation at the preset rated operating frequency; and giving visual and acoustic warnings every time the occurrence of a malfunction is detected during the first through the fourth tests.

It is preferable that the method for conducting performance tests of an air conditioner by operation modes further includes the step of: accumulating check results from the first through the fourth checks and displaying, on a monitor, the accumulated check results as final performance test results.

Further, it is preferable that the visual and acoustic warnings include blinking LED light and outputting intermittent speaker sounds.

Further, it is preferable that the method for conducting performance tests of an air conditioner by operation modes further include the step of: giving visual and acoustic warnings when the performance tests on the air conditioner are completed.

Further, it is also preferable that the various kinds of preset performances include at least one of vibration level, noise level, existence of compression defects, switching state of the four-way valve, and normal operational states of sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments, given in conjunction with the accompanying drawings, in which:

FIG. 1 shows an overall structural view of a typical air conditioner system;

FIG. 2 illustrates an exemplary block diagram of a performance testing system for an air conditioner in accordance with an embodiment of the present invention; and

FIGS. 3A and 3B are flowcharts for describing a performance testing method for an air conditioner in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As will be described below, in accordance with the present invention, an air conditioner is mounted on a test loader capable of conducting performance tests by operation modes, which are automatically switched in order of a cooling operation mode at a preset lowest operating frequency, a heating operation mode at a preset lowest operating frequency, a cooling operation mode at a preset rated operating frequency, and a heating operation mode at a preset rated operating frequency, and performance test results in each operation mode are given in visible and acoustic alarms whenever performance testing in each operation mode is finished, unlike the above-mentioned conventional performance testing method in which an engineer manually conducts performance tests in each operation mode by switching the operation mode of an air conditioner. Using this technical unit makes it easier to accomplish the objects of the invention.

FIG. 2 illustrates an exemplary block diagram of a performance testing system for an air conditioner in accordance with an embodiment of the present invention. The inventive performance testing system includes an operating block 202, a control block 204, a test loader 206, a vibration sensor 210, a noise sensor 212, a monitor 214, a speaker 216, and a display 218.

Referring to FIG. 2, the operating block 202 is constituted by a plurality of operation keys used for various operation controls of the testing system. It functions to generate a test execution signal for executing test modes in accordance with the invention in response to user operation, and transfer the signal to the control block 204.

Next, the control block 204 includes a microprocessor, for example, performing the overall operational control of the testing system. When the test execution signal is inputted from the operating block 202 with an air conditioner 208 being mounted (loaded) on the test loader 206, the control block 204 controls the operation of the air conditioner 208. That is, the control block 204 provides an execution control function for each operation mode, in which the air conditioner is set to a cooling operation mode and is running at a preset lowest operating frequency for a specified amount of time; switches to a heating operation mode to run at a preset lowest operating frequency for a specified amount of time; switches to a cooling operation mode to run at a preset rated operating frequency for a specified amount of time; and switches to a heating operation mode to run at a preset rated operating frequency for a specified amount of time.

Here, the operation mode at a lowest frequency stands for an operation mode that executes a start control and a normal control, under conditions where the operating frequency of a compressor is fixed to a lowest frequency (e.g., 30 Hz), the pulse value of an electronic expansion valve is set to a value calculated based on cooling/heating load amount, an indoor fan is at low state, and an outdoor fan is set to 650 RPM. In addition, the operation mode at a rated frequency represents an operation mode that executes a start control and a normal control, under conditions where the operating frequency of the compressor is fixed to a rated frequency (e.g., 56 Hz), the pulse value of the electronic expansion valve is set to a value calculated based on cooling/heating load amount, the indoor fan is at high state, and the outdoor fan is set to 650 RPM.

The control block 204 provides a variety of functions such as checking whether a kind of preset performances are normal or abnormal based on sensing signals generated by the vibration and the noise sensors 210 and 212 and an output signal from the air conditioner 208 loaded on the test loader 206 every time each operation mode (that is, a cooling operation mode at the lowest operating frequency, a heating operation mode at the lowest operating frequency, a cooling operation mode at the rated operating frequency, and a heating operation mode at the rated operating frequency) is executed. Here, examples of the kind of preset performance tests include, for example, vibration level, noise level, existence of compression defects, switching state of the four-way valve, normal operational states of sensors, and so on.

Moreover, when a malfunction is detected in any performance during the procedure of performance testing in each operation mode, the control block 204 offers the function of generating a guidance message and a control signal for giving visible and acoustic alarms, and then sending them to the monitor 214, the speaker 216, and the display 218.

The test loader 206 is for loading the air conditioner 208 to be tested. The air conditioner 208 loaded on such a test loader 206 performs such functions as power ON/OFF, operation mode execution, operation mode switching, etc., in response to various control signals provided from the control block 204, and generates an output signal, a four-way valve switching state signal, a sensor operating signal, and the like, and transfers them to the control block 204 when various operation modes are executed.

On the other hand, although not shown in detail in FIG. 2, it may be of course configured in a manner that the air conditioner 208 is automatically loaded on the test loader 206 in a conveyor loading way, and is unloaded to outside in a conveyor unloading way after performance testing is finished.

The vibration and the noise sensors 210 and 212 sense vibration and noise in the air conditioner 208 loaded on the test loader 206, respectively, when the air conditioner 208 is running in various operation modes (that is, a cooling operation mode at the lowest operating frequency, a heating operation mode at the lowest operating frequency, a cooling operation mode at the rated operating frequency, and a heating operation mode at the rated operating frequency). The vibration and noise signals sensed by the sensors are then sent to the control block 204.

The monitor 214 displays a warning message provided from the control block 204 when an abnormal performance is detected in any of the operation modes. When performance testing on the air conditioner 208 is over, the speaker 216 gives performance test results in an acoustic alarm in response to an acoustic alarm control signal provided from the control block 204. The display 218 can be constituted by an LED and the like to give performance test results in a visible alarm in response to a visible alarm control signal provided form the control block 204.

For example, when all performances of an air conditioner are in normal state, the speaker 216 may generate a prolonged “beep” sound once, and the display 218 may be lighted (indicating good quality of the air conditioner). On the other hand, when any type of malfunction is detected in the air conditioner, the speaker 216 may generate short intermittent sounds like “beep, beep, beep . . . ”, and the display 218 may blink (warning a defect in the air conditioner).

If performance tests in all operation modes have been finished, the control bock 204 generates performance test result values (e.g., test result values in the shape of graph) by operation modes, and transfers the same to the monitor 214. Consequently, if there is any malfunction in the air conditioner, an engineer (or worker) can easily learn what part or which function has a problem, simply by looking at the performance test result values that are displayed on the monitor 214.

In short, the testing system of the invention can conduct performance testing in an automatic manner by automatically switching the operation mode of an air conditioner to be tested on the test loader at fixed time intervals in response to the test execution operation by the engineer, and gives the performance test results in each operation mode both visually and acoustically. Therefore, the inventive testing system can remarkably reduce the time spent in performance testing on an air conditioner and enhance the reliability of performance tests, compared with the conventional testing system.

Now, a stepwise procedure of the automatic, high-speed performance testing on an air conditioner in accordance with the invention will be described through the use of the testing system with the constitution set forth above.

FIGS. 3A to 3B is a flowchart for describing a performance testing method for an air conditioner in accordance with another embodiment of the present invention.

Referring to FIGS. 3A to 3B, when the air conditioner 208 to be tested is loaded on the test loader 206 of the testing system at step S302, the control block 204 checks at step S304 whether a testing mode execution signal according to user operation is inputted from the operating block 202.

In result of the checking in step S304, if the testing mode execution signal is inputted, the control block 204 sets the operation mode of the air conditioner to a cooling operation at the lowest operating frequency, and executes the operation at step S306. At this time, the operation mode at the lowest frequency includes a start control and a normal control.

For instance, the start control and the normal control in the cooling operation mode at the lowest frequency are executed under conditions where the operating frequency of a compressor is fixed to a lowest frequency (e.g., 30 Hz), the pulse value of an electronic expansion valve is set to a value calculated based on cooling/heating load amounts, an indoor fan is at low state, and an outdoor fan is set to 650 RPM.

When the air conditioner 208 is running in the cooling operation mode at the lowest operating frequency as described above, the vibration sensor 210 and the noise sensor 212 provide a sensed vibration signal and a sensed noise signal to the control block 204, respectively. Also, an output signal, a four-way valve switching state check signal, and signals indicating operational states of the sensors are provided from the air conditioner 208 to the control block 204.

In response, the control block 204 compares the sensed vibration signal and the sensed noise signal with a threshold vibration level value and a threshold noise level value that are preset and stored in an internal memory, respectively, to detect whether degrees of vibration and noise exceed the preset threshold values. Moreover, the control block 204 decides, based on the output signal, the four-way valve switching state check signal and the signals indicating operational states of the sensors from the air conditioner 208, whether there are compression defects, whether switching state of the four-way valve is abnormal, whether various sensors (e.g., a pressure sensor, a temperature sensor, etc.) are operated normally, and so forth. In other words, the control block 204 checks at step S308 if there is any malfunction in the cooling operation mode at the lowest operating frequency.

In result of the checking in step S308, if there is no problem in every performance testing item, the procedure goes to step S314, in which the control block 204 switches the operation mode of the air conditioner 208 to a heating operation so that the air conditioner 208 may operate in a heating operation mode at the lowest operating frequency.

Contrarily to the above, however, if a malfunction was detected in at least one of specific check items during the cooling operation at the lowest operating frequency, the control block 204 controls the generation of a warning message in that mode. That is, the control block 204 generates a malfunction message indicating an item with the occurrence of a malfunction to transfer it to the monitor 214, and generates visible and acoustic alarm control signals for alarming the occurrence of a malfunction visually and acoustically to transfer them to the speaker 216 and the display 218, respectively, at step S310.

In consequence, a message for alarming the occurrence of a malfunction in the cooling operation mode at the lowest operating frequency is displayed on the monitor 214, an acoustic alarm sound (for example, short “beep, beep, beep . . . ” intermittent sounds) is generated from the speaker 216, and a visible alarm (for example, blinking LED light) is indicated on the display 218. The warning and alarm messages outputted during the cooling operation at the lowest operating frequency are provided only for a specified amount of time (for example, 3 sec, 6 sec, 9 sec, etc.). After the specified amount of time elapses, the procedure goes back to step S314 to proceed with subsequent steps.

Next, the control block 204 collects and stores information associated with the occurrence of any malfunction during the cooling operation mode at the lowest operating frequency in the internal memory at step S312. The reason for collection of the information concerning the occurrence of any malfunction is to help the engineer more easily and clearly see the performance test results in each operation mode being displayed on the monitor when the performance testing on the air conditioner is completed.

In the meantime, when the operation mode switches at step S314 and the air conditioner 208 is running in a heating operation mode at the lowest operating frequency at step S316, the same processes in step S308 are carried out, i.e., the control block 204 checks at step S318 whether vibration and noise have exceeded their preset thresholds, whether there are compression defects, whether switching state of the four-way valve is abnormal, whether various sensors are operated normally, and so forth.

In result of the checking in step S318, if there is no problem in every performance testing item during the heating operation at the lowest operating frequency, the procedure goes to step S324, in which the control block 204 switches the operation mode of the air conditioner 208 to a cooling operation so that the air conditioner 208 may operate in a cooling operation mode at the rated operating frequency.

Contrarily to the above, however, if a malfunction was detected by the checking in step S318 in at least one of specific check items during the heating operation at the lowest operating frequency, the control block 204 controls the generation of a warning message in that mode. That is, the control block 204 generates a malfunction message indicating an item with the occurrence of a malfunction to transfer it to the monitor 214, and generates visible and acoustic alarm control signals for alarming the occurrence of a malfunction visually and acoustically to transfer them to the speaker 216 and the display 218, respectively, at step S320.

In consequence, a message for alarming the occurrence of a malfunction in the heating operation mode at the lowest operating frequency is displayed on the monitor 214, an acoustic alarm sound (for example, short “beep, beep, beep . . . ” intermittent sounds) is generated from the speaker 216, and a visible alarm (for example, blinking LED light) is indicated on the display 218. The warning and alarm messages outputted during the heating operation at the lowest operating frequency are provided only for a specified amount of time (for example, 3 sec, 6 sec, 9 sec, etc.). After the specified amount of time elapses, the procedure goes back to the step S324 to proceed with subsequent steps.

Next, the control block 204 collects and stores information concerning the occurrence of any malfunction during the heating operation at the lowest operating frequency in the internal memory at step S322.

Subsequently, when the operation mode switches at step S324 and the air conditioner 208 is running in a cooling operation mode at the rated operating frequency at step S326, the same processes in steps S308 to S316 are carried out, i.e., the control block 204 checks at step S328 whether vibration and noise have exceeded their preset thresholds, whether there are compression defects, whether switching state of the four-way valve is abnormal, whether all sensors are operated normally, and so forth.

For example, a variety of performance tests are done by executing an operation mode that performs a start control and a normal control under conditions where the operating frequency of the compressor is fixed to a rated frequency (e.g., 56 Hz), the pulse value of the electronic expansion valve is set to a value calculated based on cooling/heating load amounts, the indoor fan is at high state, and the outdoor fan is set to 650 RPM.

In result of the checking in step S328, if there is no problem in every performance testing item during the cooling operation at the rated operating frequency, the procedure goes to step S334, in which the control block 204 switches the operation mode of the air conditioner 208 to a heating operation so that the air conditioner 208 may operate in a heating operation mode at the rated operating frequency.

Contrarily to the above, however, if a malfunction was detected by the checking in step S328 in at least one of specific check items during the cooling operation at the rated operating frequency, the control block 204 controls the generation of a warning message in that mode. That is, the control block 204 generates a malfunction message indicating an item with the occurrence of a malfunction to transfer it to the monitor 214, and generates visible and acoustic alarm control signals for alarming the occurrence of a malfunction visually and acoustically to transfer them to the speaker 216 and the display 218, respectively, at step S330.

In consequence, a message for alarming the occurrence of a malfunction in the cooling operation mode at the rated operating frequency is displayed on the monitor 214, an acoustic alarm sound (for example, short “beep, beep, beep . . . ” intermittent sounds) is generated from the speaker 216, and a visible alarm (for example, blinking LED light) is indicated on the display 218. The warning and alarm messages outputted during the cooling operation at the rated operating frequency are provided only for a specified amount of time (for example, 3 sec, 6 sec, 9 sec, etc.). After the specified amount of time elapses, the procedure goes back to step S334 to proceed with subsequent steps.

Thereafter, the control block 204 collects and stores information concerning the occurrence of any malfunction during the cooling operation at the rated operating frequency in the internal memory at step S332.

Next, when the procedure goes to step S334 to switch the operation mode and the air conditioner 208 is running in a heating operation mode at the rated operating frequency at step S336, the same processes in step S328 are carried out, i.e., the control block 204 checks whether vibration and noise have exceeded their preset thresholds, whether there are compression defects, whether switching state of the four-way valve is abnormal, whether various sensors are operated normally, and so forth at step S338.

In result of the checking in step S338, if there is no problem in every performance testing item during the heating operation at the rated operating frequency, the procedure goes to step S344 that provides a test result message, as set forth later.

Contrarily to the above, however, if a malfunction was detected by the checking in step S338 in at least one of specific check items during the heating operation at the rated operating frequency, the control block 204 controls the occurrence of a warning message in that mode. That is, the control block 204 generates a malfunction message indicating an item with the occurrence of a malfunction to transfer it to the monitor 214, and generates visible and acoustic alarm control signals for alarming the occurrence of a malfunction visually and acoustically to transfer them to the speaker 216 and the display 218, respectively, at step S340.

In consequence, a message for alarming the occurrence of a malfunction in the heating operation mode at the rated operating frequency is displayed on the monitor 214, an acoustic alarm sound (for example, short “beep, beep, beep . . . ” intermittent sounds) is generated from the speaker 216, and a visible alarm (for example, blinking LED light) is indicated on the display 218. The warning and alarm messages outputted during the heating operation at the rated operating frequency are provided only for a specified amount of time (for example, 3 sec, 6 sec, 9 sec, etc.). After the specified amount of time elapses, the procedure goes back to the step S344 to proceed with subsequent steps.

Thereafter, the control block 204 collects and stores information concerning the occurrence of any malfunction during the heating operation at the rated operating frequency in the internal memory at step S342.

If the performance testing on an air conditioner in all modes that consist of a cooling operation mode at the lowest operating frequency, a heating operation mode at the lowest operating frequency, a cooling operation mode at the rated operating frequency, and a heating operation mode at the rated operating frequency has been finished through a series of processes described so far, the control block 204 reads the performance test result data from the internal memory, creates a test result message, for example, a list of test results (indicating a malfunction) classified by operation modes, and transfers the list to the monitor 214 at step S344.

Consequently, the air conditioner performance test result values classified by operation modes are displayed on the monitor 214, so that the engineer can easily discriminate good or bad quality of the air conditioner by naked eyes, and utilize the results for maintenance of and repairing a malfunction in any performance of a specific operation mode, if any.

In this way, performance tests on the air conditioner according to the invention are completed through the performance testing by operation modes as explained above at step S346.

Alternatively, in order that the engineer can more easily recognize the completion of the performance tests visually and acoustically when all of the performance tests on the air conditioner are completed, prolonged intermittent sounds that are relatively longer than the intermittent sounds used for warning a malfunction may be outputted through the speaker for a predetermined time period, or the display may be lighted to signal the completion of the testing.

That is to say, in accordance with the present invention, the air conditioner to be tested is loaded on the test loader, and operates automatically in order of a cooling operation mode at the lowest operating frequency, a heating operation mode at the lowest operating frequency, a cooling operation mode at the rated operating frequency, and a heating operation mode at the rated operating frequency. When any malfunction of performance is detected in each operation mode, visible and acoustic alarms are given, so that the performance testing system of the present invention can markedly reduce the time spent in performance testing on an air conditioner and drastically enhance the reliability of performance tests, compared with the conventional testing system set forth above.

As mentioned above, in accordance with the present invention, an air conditioner is mounted on a test loader capable of conducting performance tests by operation modes, which are automatically switched in order of a cooling operation mode at a preset lowest operating frequency, a heating operation mode at a preset lowest operating frequency, a cooling operation mode at a preset rated operating frequency, and a heating operation mode at a preset rated operating frequency, and performance test results in each operation mode are given in visible and acoustic alarms whenever performance testing in each operation mode is finished, unlike the above-mentioned conventional performance testing method in which an engineer manually conducts performance tests in each operation mode by switching the operation mode of an air conditioner. As a result, the performance testing system of the invention can markedly reduce the time spent in performance testing on an air conditioner and drastically enhance the reliability of performance tests, compared with the above-stated general testing system.

While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modification may be made without departing from the spirit and scope of the invention as defined in the following claims. 

1. A system for conducting performance tests of an air conditioner by operation modes, the system comprising: a test loader for loading an air conditioner to be tested; a control unit for switching the operation modes in order of cooling and heating operation modes at a lowest operating frequency and cooling and heating operation modes at a rated operating frequency to execute the switched operation modes; a checking unit for checking the existence of a malfunction in preset performances whenever each of the operation modes is executed; and a warning unit for warning the check result on the existence of a malfunction in each of the operation modes.
 2. The system of claim 1, further comprising: a display unit for displaying, on a monitor, the check results as final performance test results.
 3. The system of claim 1, wherein the warning unit includes: an LED for visually displaying the check result on the existence of a malfunction in each of the operation modes; and a speaker for acoustically warning the check result on the existence of a malfunction in each of the operation modes.
 4. The system of any one of claims 1 to 3, wherein the preset performances include at least one of vibration level, noise level, existence of compression defects, switching state of a four-way valve, and normal operational states of sensors.
 5. A method for conducting performance tests of an air conditioner by operation modes, the method comprising the steps of: loading the air conditioner to be tested on a test loader; operating the air conditioner in a cooling operation mode at a preset lowest operating frequency; performing a first check on the existence of a malfunction in preset performances during the cooling operation for a specified period time; switching the air conditioner to a heating operation mode after the first check is executed for a specified period of time; operating the air conditioner in the heating operating mode at the preset lowest operating frequency to conduct a second check on the existence of a malfunction in preset performances; switching the air conditioner to a cooling operation mode after the second check is executed for a specified amount of time, and operating the air conditioner at a preset rated operating frequency; carrying out a third check on the existence of a malfunction in preset performances during the cooling operation at the preset rated operating frequency; switching the air conditioner to a heating operation mode after the third check is executed for a specified period of time; operating the air conditioner at the preset rated operating frequency to conduct a fourth check on the existence of a malfunction in preset performances; and giving warnings every time the occurrence of a malfunction is detected during the first through the fourth tests.
 6. The method of claim 5, further comprising the step of: accumulating check results from the first through the fourth checks; and displaying, on a monitor, the accumulated check results as final performance test results.
 7. The method of claim 6, wherein the include blinking LED light and outputting intermittent speaker sounds.
 8. The method of any one of claims 5 to 7, further comprising the step of: giving visual and acoustic warnings when the performance tests on the air conditioner are completed.
 9. The method of any one of claims 5 to 7, wherein the preset performances include at least one of vibration level, noise level, existence of compression defects, switching state of a four-way valve, and normal operational states of sensors. 